What effect does adding salt have on the freezing point of water?

Adding salt to water lowers the freezing point of the water, a phenomenon known as freezing point depression. This occurs because the presence of salt ions disrupts the formation of ice crystals. When salt is dissolved in water, it breaks down into its constituent ions (sodium and chloride), which interferes with the hydrogen bonds that would normally form in pure water as it freezes.

As a result, the temperature at which water will freeze becomes lower than the standard 0 degrees Celsius (32 degrees Fahrenheit). This principle is commonly observed in everyday situations, such as the use of salt on icy roads in winter to prevent ice formation. By lowering the freezing point, salt allows the water to remain liquid at temperatures where it would normally freeze, improving safety and vehicle traction on roads.